package com.mmz.gulimall.search.service.impl;

import com.alibaba.fastjson.JSON;
import com.mmz.common.to.SkuEsModel;
import com.mmz.gulimall.search.config.GulimallElasticsearchConfig;
import com.mmz.gulimall.search.constant.EsConstant;
import com.mmz.gulimall.search.service.MallSearchService;
import com.mmz.gulimall.search.vo.SearchParam;
import com.mmz.gulimall.search.vo.SearchResult;
import org.apache.lucene.search.join.ScoreMode;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.index.query.*;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.search.SearchHits;
import org.elasticsearch.search.aggregations.*;
import org.elasticsearch.search.aggregations.bucket.nested.NestedAggregationBuilder;
import org.elasticsearch.search.aggregations.bucket.nested.ParsedNested;
import org.elasticsearch.search.aggregations.bucket.terms.ParsedLongTerms;
import org.elasticsearch.search.aggregations.bucket.terms.ParsedStringTerms;
import org.elasticsearch.search.aggregations.bucket.terms.Terms;
import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregationBuilder;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightBuilder;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightField;
import org.elasticsearch.search.sort.SortOrder;
import org.springframework.stereotype.Service;
import org.springframework.util.StringUtils;

import javax.annotation.Resource;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;

@Service
public class MallSearchServiceImpl implements MallSearchService {
    @Resource
    private RestHighLevelClient restHighLevelClient;

    /**
     * es检索商品
     *
     * @param searchParam 检索参数
     * @return 检索结果
     */
    @Override
    public SearchResult search(SearchParam searchParam) {
        //1、动态构建出查询需要的DSL语句
        SearchResult result = null;

        //1、准备检索请求
        SearchRequest searchRequest = buildSearchRequrest(searchParam);
        try {
            //2、执行检索请求
            SearchResponse searchResponse = restHighLevelClient.search(searchRequest, GulimallElasticsearchConfig.COMMON_OPTIONS);

            //3、分析响应数据封装成我们需要的格式
            result = buildSearchResult(searchResponse, searchParam);
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * 构建我们需要的检索请求
     *
     * @param searchResponse
     * @return
     */
    private SearchResult buildSearchResult(SearchResponse searchResponse, SearchParam param) {
        SearchResult result = new SearchResult();
        //1、返回所有查询到的商品信息
        SearchHits hits = searchResponse.getHits();
        List<SkuEsModel> esModels = new ArrayList<>();
        if (hits.getHits() != null && hits.getHits().length > 0) {
            for (SearchHit hit : hits.getHits()) {
                String sourceAsString = hit.getSourceAsString();
                SkuEsModel esModel = JSON.parseObject(sourceAsString, SkuEsModel.class);
                //存在查询，显示高亮
                if (!StringUtils.isEmpty(param.getKeyword())){
                    HighlightField skuTitle = hit.getHighlightFields().get("skuTitle");
                    String HighlightString = skuTitle.getFragments()[0].string();
                    esModel.setSkuTitle(HighlightString);
                }
                esModels.add(esModel);
            }
        }
        result.setProducts(esModels);
        //==============从聚合中信息==============
        //2、当前所有商品涉及到的所有属性信息
        List<SearchResult.AttrVo> attrVos = new ArrayList<>();
        ParsedNested attr_agg = searchResponse.getAggregations().get("attr_agg");
        ParsedLongTerms attr_id_agg = attr_agg.getAggregations().get("attr_id_agg");
        for (Terms.Bucket bucket : attr_id_agg.getBuckets()) {
            SearchResult.AttrVo attrVo = new SearchResult.AttrVo();
            //1.得到属性的ID
            long attrId = bucket.getKeyAsNumber().longValue();
            //2.得到属性的名称
            String attrName = ((ParsedStringTerms) bucket.getAggregations().get(("attr_name_agg"))).getBuckets().get(0).getKeyAsString();
            //3.得到属性的所有值
            List<String> attrValues = ((ParsedStringTerms) bucket.getAggregations().get("attr_value_agg")).getBuckets().stream().map(item -> {
                String keyAsString = ((Terms.Bucket) item).getKeyAsString();
                return keyAsString;
            }).collect(Collectors.toList());
            attrVo.setAttrId(attrId);
            attrVo.setAttrName(attrName);
            attrVo.setAttrValue(attrValues);

            attrVos.add(attrVo);
        }
        result.setAttrs(attrVos);

        //3、当前所有商品涉及到的所有品牌信息
        List<SearchResult.BrandVo> brandVos = new ArrayList<>();
        ParsedLongTerms brand_agg = searchResponse.getAggregations().get("brand_agg");
        for (Terms.Bucket bucket : brand_agg.getBuckets()) {
            SearchResult.BrandVo brandVo = new SearchResult.BrandVo();
            //1.得到品牌id
            long brandId = bucket.getKeyAsNumber().longValue();
            brandVo.setBrandId(brandId);
            //2.得到品牌名
            String brandName = ((ParsedStringTerms) bucket.getAggregations().get("brand_name_agg")).getBuckets().get(0).getKeyAsString();
            brandVo.setName(brandName);
            //3.得到品牌图片
            String brandImg = ((ParsedStringTerms) bucket.getAggregations().get("brand_img_agg")).getBuckets().get(0).getKeyAsString();
            brandVo.setLogo(brandImg);

            brandVos.add(brandVo);
        }
        result.setBrands(brandVos);
        //4、当前所有商品涉及到的所有分类信息
        ParsedLongTerms catalog_agg = searchResponse.getAggregations().get("catalog_agg");
        List<? extends Terms.Bucket> buckets = catalog_agg.getBuckets();
        List<SearchResult.CatalogVo> catalogVos = new ArrayList<>();
        for (Terms.Bucket bucket : buckets) {
            SearchResult.CatalogVo catalogVo = new SearchResult.CatalogVo();
            //得到分类id
            String keyAsString = bucket.getKeyAsString();
            catalogVo.setCatalogId(Long.parseLong(keyAsString));

            //得到分类名
            ParsedStringTerms catalog_name_agg = bucket.getAggregations().get("catalog_name_agg");
            String catalog_name = catalog_name_agg.getBuckets().get(0).getKeyAsString();
            catalogVo.setCatalogName(catalog_name);

            catalogVos.add(catalogVo);
        }
        result.setCatalogs(catalogVos);
        //5、分页信息-当前页码、总记录数、总页码
        long total = hits.getTotalHits().value;
        //5.1 设置总记录数
        result.setTotal(total);
        //5.2 计算总页码
        Integer totalPages = (int) total % EsConstant.PRODUCT_PAGESIZE == 0 ? (int) total % EsConstant.PRODUCT_PAGESIZE : ((int) total % EsConstant.PRODUCT_PAGESIZE + 1);
        result.setTotalPages(totalPages);
        result.setPageNum(param.getPageNum());
        return result;
    }

    /**
     * 构建检索请求
     * 模糊匹配，过滤（属性，分类，品牌，价格区间，库存），排序，分页，高亮，聚合分析
     *
     * @return
     */
    private SearchRequest buildSearchRequrest(SearchParam searchParam) {
        //构建DSL语句
        SearchSourceBuilder searchBuilder = new SearchSourceBuilder();
        /**
         * 查询，过滤（属性，分类，品牌，价格区间，库存）
         */
        //1、构建bool - query
        BoolQueryBuilder boolQuery = QueryBuilders.boolQuery();
        //1.1、must-模糊匹配
        if (!StringUtils.isEmpty(searchParam.getKeyword())) {
            boolQuery.must(QueryBuilders.matchQuery("skuTitle", searchParam.getKeyword()));
        }

        //1.2、bool-filter -按三级分类ID查询
        if (searchParam.getCatalog3Id() != null) {
            boolQuery.filter(QueryBuilders.termQuery("catalogId", searchParam.getCatalog3Id()));
        }
        //1.2、bool-filter -按品牌ID查询
        if (searchParam.getBrandId() != null && searchParam.getBrandId().size() > 0) {
            boolQuery.filter(QueryBuilders.termsQuery("brandId", searchParam.getBrandId()));
        }
        //1.2、bool-filter -按所有指定的属性进行查询
        if (searchParam.getAttrs() != null && searchParam.getAttrs().size() > 0) {

            for (String attrStr : searchParam.getAttrs()) {
                //例如：attrs=1_5寸:8寸&attrs=2_8G:16G
                BoolQueryBuilder nestedBoolQuery = QueryBuilders.boolQuery();
                //attrs=1_5寸:8寸
                String[] s = attrStr.split("_");
                String attrId = s[0];
                //该属性的检索用的值
                String[] attrValues = s[1].split(":");
                nestedBoolQuery.must(QueryBuilders.termQuery("attrs.attrId", attrId));
                nestedBoolQuery.must(QueryBuilders.termQuery("attrs.attrValue", attrValues));
                //每个nest都必须生成一个nested查询
                NestedQueryBuilder nestedQuery = QueryBuilders.nestedQuery("attrs", nestedBoolQuery, ScoreMode.None);
                boolQuery.filter(nestedQuery);
            }
        }
        //1.2、bool-filter -按是否有库存进行查询
        boolQuery.filter(QueryBuilders.termQuery("hasStock", searchParam.getHasStock() == 1));

        //1.2、bool-filter -按价格区间查询
        if (!StringUtils.isEmpty(searchParam.getSkuPrice())) {
            /**
             * 1_500/_500/500_
             * "range":{
             *     "skuPrice":{
             *         "gte":0
             *         "lte":6000
             *     }
             * }
             */
            RangeQueryBuilder rangeQuery = QueryBuilders.rangeQuery("skuPrice");
            String[] s = searchParam.getSkuPrice().split("_");
            if (s.length == 2) {
                //区间
                rangeQuery.gte(s[0]).lte(s[1]);
            } else if (s.length == 1) {
                if (searchParam.getSkuPrice().startsWith("_")) {
                    rangeQuery.lte(s[0]);
                }
                if (searchParam.getSkuPrice().endsWith("_")) {
                    rangeQuery.gte(s[0]);
                }
            }
        }

        //把以前的所有条件都拿来进行封装
        searchBuilder.query(boolQuery);

        /**
         * 排序，分页，高亮
         */
        //2.1排序
        if (!StringUtils.isEmpty(searchParam.getSort())) {
            String sort = searchParam.getSort();
            //sort = hotScore_asc/desc
            String[] s = sort.split("_");
            SortOrder order = s[1].equalsIgnoreCase("asc") ? SortOrder.ASC : SortOrder.DESC;
            searchBuilder.sort(s[0], order);
        }
        //2.2分页
        //pageNum：1 form：0 size：5  0.1.2.3.4
        //pageNum：2 form：5 size：5  5.6.7.8.9
        //form = (pageNum-1)*size
        searchBuilder.from((searchParam.getPageNum() - 1) * EsConstant.PRODUCT_PAGESIZE);
        searchBuilder.size(EsConstant.PRODUCT_PAGESIZE);
        //2.3 高亮
        if (!StringUtils.isEmpty(searchParam.getKeyword())) {
            HighlightBuilder highlightBuilder = new HighlightBuilder();
            highlightBuilder.field("skuTitle");
            highlightBuilder.preTags("<b style='color:red'>");
            highlightBuilder.postTags("</b>");
            searchBuilder.highlighter(highlightBuilder);
        }


        /**
         * 聚合分析
         */
        /**聚合brand*/
        //1、品牌聚合
        TermsAggregationBuilder brand_agg = AggregationBuilders.terms("brand_agg");
        brand_agg.field("brandId").size(50);
        //1.1品牌聚合的子聚合
        brand_agg.subAggregation(AggregationBuilders.terms("brand_name_agg").field("brandName").size(1));
        brand_agg.subAggregation(AggregationBuilders.terms("brand_img_agg").field("brandImg").size(1));
        searchBuilder.aggregation(brand_agg);

        /**聚合bcatalog*/
        //2、分类聚合 catalog_agg
        TermsAggregationBuilder catalog_agg = AggregationBuilders.terms("catalog_agg").field("catalogId");
        //2.1分类的子聚合
        catalog_agg.subAggregation(AggregationBuilders.terms("catalog_name_agg").field("catalogName").size(1));
        searchBuilder.aggregation(catalog_agg);

        /**聚合attr*/
        //3、属性聚合 attr_agg
        NestedAggregationBuilder attr_agg = AggregationBuilders.nested("attr_agg", "attrs");
        //聚合出当前所有的attrId
        TermsAggregationBuilder attr_id_agg = AggregationBuilders.terms("attr_id_agg").field("attrs.attrId");
        //聚合分析出当前attr_id对应的名字
        attr_id_agg.subAggregation(AggregationBuilders.terms("attr_name_agg").field("attrs.attrName").size(1));
        //聚合分析出当前attr_id对应的所有可能的属性值attrValue
        attr_id_agg.subAggregation(AggregationBuilders.terms("attr_value_agg").field("attrs.attrValue").size(50));
        attr_agg.subAggregation(attr_id_agg);

        SearchRequest searchRequest = new SearchRequest(new String[]{EsConstant.PRODUCT_INDEX}, searchBuilder);
        return searchRequest;
    }
}
